Questions tagged [experimental-technique]
filling in the unspecified details of elegant-sounding descriptions of experimental methods.
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Experiments check out theories but who or what checks out the experiments? [closed]
There is a classic saying which goes more or less like this:
If your theory is not verified by the experiment then it is wrong!
Specifically for the field of particle physics, lately experiments ...
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Measuring radius vs diameter for a circular ring?
Consider an experiment where I have to measure the radius of a circular ring diffraction (or interference) pattern (think Newton's rings).
It is advised to measure the diameter and then divide it by ...
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Single slit diffraction with a slit width much larger than the wavelength
It is known that for a diffraction pattern to be strong, the wavelength of incoming laser light should be comparable to the slit size.
The reason being if the slit is very narrow it effectly is a ...
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How can we conduct experiments to verify formulas without special equipment? How was it done in the past?
If we wanted to verify experimentally/empirically as laymen without special instruments a formula such as $s=16t^2$ which is used to approximate the distance s, in feet, that an object falls freely ...
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Understanding the 'Truncated DFT' for Moiré Phase Analysis
I am researching the use of a Moiré sampling algorithm in order to determine the two-dimensional displacement field of an object. In the paper of Wang and Ri (2022), the algorithm is described. ...
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What is a proper resolution, and how many times of measurement needed for a credible experiments? [closed]
This question aims to understand a basic intuitive understanding and proper doing in practical situations for designing experiments.
Resolution
Suppose there is an object large as a hand. What is ...
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Charge separation by friction: Experimental problem
In introductory electrostatics one often sees an experiment where the instructor rubs a rod (for example a PVC or a glass rod) with a cloth (for example made of wool, cotton or silk). And then strips ...
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Can laser diode characteristics comparison be based on laser of one length?
As we know, e.g. from this website, to know the laser Transparency Threshold Current and Internal Quantum Efficiency, we need the LI curves from lasers of various widths.
However sometimes it is ...
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What are the sealing adhesives for high vacuum system?
Recently, I have a project that needs to use a high vacuum system. During the construction process, I encountered a problem: I need to stick mica or glass to the window of the copper wall (one side is ...
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One-way speed of light confirmation, not measurement [duplicate]
So there's quite a few posts on here about the now infamous YT video about how the speed of light can only be measured as a round trip. I think I understand the issues with the proposed experiments I'...
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What are some physical or mathematical conecepts/techniques that can be used to "easily" do numerical experiments/analyses in physics? [closed]
Basically I'm asking for concepts/techniques (don't know if it's the right word) that can be used/applied "easily" to eg. a physical system. It might be used to identify a behavior or a ...
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How can neutral, even-numbered atoms like strontium be trapped in a magnetic trap?
Since the beginning of this year, there has been a lot of attention paid to newly-created 'Pauli crystals', also known as 'Pauli-blocking crystals'......
Using ionized atoms, or at least odd- numbered ...
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How can we detect neutrons?
If I am asked to design a simple experiment to detect neutrons, how can I do that?
The problem is, neutron is a neutral particle. So, application of electric and magnetic fields won't help. Can I ...
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What is required for a minimum viable Bell test experiment at home?
My objective is to create a tabletop Bell test experimental setup generating data of suitable quality for undergraduate education or satisfaction of personal curiosity; remaining free from loopholes ...
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How to get FFT spectrum of acceleration measurement?
I use an Accelerometer to measure acceleration (normalized via the gravitational acceleration $g\simeq9.81\,m/s^2$, so if one axis is orthogonal to the ground it returns the value 1). I already ...
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What is the maximum virtual depth achievable in a printed hologram?
I remember a few years ago printed holograms were quite fashionable. Even though they still had different colors from reality, I found them quite impressing.
I wonder if there has been any progress in ...
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One-way speed of light experiment, no clocks or mirrors (with simulation)
As can be seen in the many creative questions here, it is hotly disputed whether you can measure the speed of light in only one direction to the point where a infamous postulate was made that the ...
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Uncertainty of angle with known uncertainty of cosine of angle
Quick question, how do I proceed if I managed to get (from some kind of a measurement) the value of $\cos(\phi)$ and its error $\sigma_{\cos\phi}$ and I'd like to find $\phi \pm \sigma_{\phi}$?
Would ...
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How do you stabilize the temperatures in your sensitive laboratory experiments?
I work in an AMO Lab, and I have been tasked with creating an experiment enclosure that will keep the air (and instruments) stable within about 50 mili-Kelvin with a set point of about 20C-21C. Our ...
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How to find thermal diffusivity
This is a question about nondimensionalization in the heat equation
$$\rho c \frac{\partial u}{\partial t}= \kappa \frac{\partial^2 u}{\partial x^2}~? $$
How could one devise a nondestructive ...
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Which one is more precise: Phase locked loop or log the waveform then do sliding FFT?
I have an experimental confusion. I am using an interferometer to monitor the movement of a translation stage by monitoring the intensity of the coaxis interference pattern of the He-Ne laser.
...
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Double Slit: Collected Data Versus Gedanken
To frame my question, I'd like to present two example quotes from articles on the double slit experiment written in respected (or at least widely read) publications:
One from Quanta:
Stranger still, ...
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How to calculate standard error for spatial average of 1D laser intensity?
I am trying to do some error analysis for an experiment involving laser diagnostics and I have a question about computing the standard error for a spatial average.
The experiment involves taking ...
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Experiment on a particle in a box
The solution of wave equation in a box gives some nodes where the wave is $0$ and there wouldn't be a particle present at any time. Did anyone confirmed that experimentally? By example one can send ...
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How can I experimentally check that the voltage in a thermocouple is generated be the gradient in the wires and not by the junction themselves?
I just found out on Wikipedia (also here and there) that the voltage in a thermocouple in not generated by the cold & hot junctions, but by the temperature gradient in the wires which generates a ...
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Has a true Superconductor ever been produced?
Having a conversation with a friend, we where discussing about the conductivity and resistance changes of superconductors.
He insisted that available superconductors produced by universities or ...
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Quantum eraser data?
Is there a website where I can get data from a quantum eraser experiment? I'm look for raw count data from the detectors.
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Realization of uniform volume charge density
A sphere with uniform volume charge density is often considered as an example in E&M. Is this a useful fiction for testing students or are there any techniques to induce a uniform volume charge ...
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How to measure $V \propto I^3$ behavior of $\text{NbSe}_2$ under its critical current?
Last week, I attempted to measure the superconductivity of multilayer NbSe${}_2$.
As one can see in figure 4 in this paper, I expected $V \propto I^3 $ behavior under its critical current $I_c$ for ...
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Determining Center of mass via string method on odd objects
This question is similar to Experiment to determine the center of mass but the answer does not fit my current experiment.
My experiment is that I need to find the center of mass of an odd object like ...
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How are 'margin of error' and 'sigma' (standard deviation) combined in a particle physics experiment?
If a particular experiment is done to determine a particular value, say the charge radius of a particle, and they give a 'sigma' of two and a 'margin of error' of a femtometer, does that mean there is ...
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Is it necessary to use a collimated light beam when using a polarizer?
I am using two polarizers (one for an halogen light source and one for a camera) to measure light reflected in parallel and perpendicular polarization setups. Should the light source used along with ...
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What is the drag coefficient of a semi-cylinder travelling at laminar region but with high Reynolds number?
For Laminar flow along a cylinder, the drag coefficient is about 1.
Question:
Can we assume that for Laminar flow along a semi-cylinder, the drag coefficient is about 0.5 because the pressure drag ...
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Scanning tunneling microscopy effect (contrast from bottom of 100 Å thick metal layer) analogous to thin-film interference and Newton's rings?
I haven't used a Green's function in 30 years and need some help understanding the use in this context.
I. B. Altfeder, D. M. Chen, and K. A. Matveev 1998 Imaging Buried Interfacial Lattices with ...
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Inverse $n^{th}$ power law for Magnetism experiment
I'm trying to read through a lab manual for showing the inverse square law of magnetism by Gauss' Method.
The following diagram is given
where M is the magnetic moment of the test magnet. $H_0$ is ...
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How to perform experiments near absolute zero temperature when the background temperature of the universe is 2.7 K?
The cosmic microwave background (CMB) radiation as a remnant from an early stage of the universe (Big Bang) is filled all space and has a thermal black body spectrum at a temperature of $2.72548±0....
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Millikan experiment: calculating $e$
Let's say we observed (or calculated) a series of measurements leading to a series of values for the charge of an oil-droplet which are grouped according to being $n\cdot e$, with $n\in\mathbb{N}$. ...
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Resource request for experimental physics and data handling
When solving questions in olympiad physics, I come across problems on experiments, data, errors, drawing graphs and extracting information from given graphs, etc. Is there any good book/resource for ...
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Experiment to determine the center of mass
Consider an axially symmetric rigid body with asymmetric mass distribution. Generally, the center of mass (and therefore moments of inertia) can be determined by knowing the center of mass of the ...
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How can I pluck a string of a guitar with a constant force?
I'm trying to perform an experiment but need ideas on how to pluck a string with a constant force using household objects/equipment.
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Error propagation with Log base 10 [closed]
I have some data and some errors for the data. The task I have been given is to $\log_{10}$ both sets of data, and then deal with the errors to plot a graph. For natural logarithms, this is easier as (...
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What is the right camera lens for imaging this experiment?
I am conducting an experiment in our lab where we are using an ICCD camera to image a very short-duration (ns) physical phenomenon. The area of interest of the test is about 25mm x 25mm and I need to ...
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Experiments to show that a voltmeter measures energy per unit charge
In "Physics for the Inquiring Mind" by Eric Rogers, an experiment is described to show that a voltmeter (considered as a black box) indeed measures work done per unit charge by measuring the ...
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Relating the Minev et al experiment to Brun QTT survey
I have been studying from many angles the groundbreaking/now renowned Minev et al experiment: To catch and reverse a quantum jump mid-flight [1]. I have many questions on this complex/intricate setup ...
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How to measure critical current of a superconducting wire, if my current source can only supply a small current?
I need to determine the critical current of an aluminum wire at 0.1Kelvin. I have access to dilution fridges, but I cannot modify the wiring in the system from room temperature to the sample space. ...
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How do non-mechanical solid-state optical switches work?
I am currently looking for a fiber-optical switch (FOS) in order to be able to change the light source of a spectrometer. As this will be used in harsh conditions, I was hoping to find a FOS with no ...
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Effect of saturated beam laser on transmission in solid materials
The transmission measurement setup commonly features a source (e.g. laser), steering mirrors, an integrating sphere, coupled to a power meter (or spectrometer). For a solid sample placed between the ...
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Lab Construction of LED
If given a semiconductor with known bandgap, how might someone construct an experimental LED within a lab? It seems common to prepare solar cells using FTO glass plates with a paste of semiconductor ...
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Why some alpha particle tracks shows curvature *without* applied magnetic field?
For the past few months I have been observing alpha tracks with my homemade expansion cloud chamber assembly, trying to replicate early achievements in particle physics using modern, low-cost ...
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Millikan oil drop experiment
I had a question about the Millikan Oil drop experiment. I did the experiment for my physics class where we had to determine the voltage that would make the droplet stationary. We did this ten times, ...
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